// 7. 使用reduce实现[1,2,3,4,9]数组中所有成员的和
const arr7 = [1, 2, 3, 4, 9];
const sum7 = arr7.reduce(function (accumulator, current) {
    return accumulator + current;
}, 0);
console.log(sum7);
// 8. 数组去重的方法 (4种)
//
let arr8 = [1, 2, 3, 1, 5, 8, 7, 2, 5, 6, 4, 2];
// 1.forEach
let newArray8 = [];
// eslint-disable-next-line no-unused-vars
arr8.forEach(function (ele, index) {
    if (!newArray8.includes(ele)) {
        newArray8.push(ele);
    }
});
console.log(newArray8);

// 2.filter,但是不是按照顺序输出，对应的数字只会取最后一次出现的位置
let newArray82 = [];
newArray82 = arr8.filter(function (ele, index, arr) {
    if (!arr.includes(ele, index + 1)) {
        return ele;
    }
});
console.log(newArray82);
// 3.map和filter连用，但是也不会按顺序输出，对应的数字只会取最后一次出现的位置
let newArray83 = [];
newArray83 = arr8
    .map(function (ele, index, arr) {
        if (!arr.includes(ele, index + 1)) {
            return ele;
        }
    })
    .filter(function (ele) {
        if (ele !== 'indefined') {
            return ele;
        }
    });
console.log(newArray83);
// 4.reduce
let newArray84 = [];
newArray84 = arr8.reduce(function (total, current) {
    if (!total.includes(current)) {
        total.push(current);
    }
    return total;
}, []);
console.log(newArray84);
